1. Field of the Invention
The present invention relates to the field of liquid crystal displays, and in particular, to a pixel unit structure, an array substrate and a display device.
2. Description of the Prior Art
Thin Film Transistor Liquid Crystal Display (TFT-LCD) occupies a leading position in the field of flat panel displays due to its advantages of small volume, low power consumption and no irradiation.
According to different forms of electric fields, LCD may be divided into various types, wherein, Advanced super Dimension Switch (ADS)-type TFT-LCD is applied widely due to its advantages of wide visual angle, high aperture ratio and high transmissibility, etc. Wherein, a multidimensional-space combination electric field is formed by a parallel electric field generated at the edge of pixel electrodes in the same plane and a longitudinal electric field generated between a pixel electrode layer and a common electrode layer, and the potential difference between the pixel electrode and the common electrode may makes a liquid crystal molecule to rotate, so that all the aligned liquid crystal molecules between and above the pixel electrodes in a liquid crystal cell can generate rotate switching, and the variation of the transmittance of the liquid crystal layer may be controlled via different potential differences, thus different gray levels may be formed on the liquid crystal display, thereby display may be implemented.
During the process of implementing the present invention, the inventors find that in the time interval of single frame, a certain potential difference between a certain pixel electrode and the common electrode must be kept, so that the liquid crystal between the pixel electrode and the common electrode is kept in a certain arrangement. However, so long as a liquid crystal display operates, the potential of the common electrode will be kept constant, thus the potential of the pixel electrode also needs to be kept unchanged in the time interval of single frame, so that a storage capacitor needs to be provided in the pixel unit, which helps to enhance the capability of maintaining potential of the pixel electrode. However, after the storage capacitor is added, the aperture ratio of the pixel unit will be reduced. At the same time, the increase of the storage capacitor means that the processes for manufacturing the mask of the pixel unit structure becomes complex, thereby the manufacturing cost of the pixel unit structure will be increased.